Scheduler for a disc drive apparatus

ABSTRACT

A scheduler ( 10 ) for a user appliance ( 1 ) and a user appliance comprising such scheduler are provided, for cooperation with a disc storage device ( 20 ). The scheduler is designed to record or read user data into or from storage space of the disc storage device, at storage locations where the amount of noise generated is as little as possible. The scheduler has an associated memory ( 7 ) with information on the noise behavior of the disc storage device ( 20 ). When selecting a storage location for writing or reading, the scheduler is designed to consult the memory ( 7 ) and to select a low-noise storage area ( 43 ).

The present invention relates in general to a storage device comprisinga rotary disc storage medium and an actuator moving a pickup over a discsurface for accessing different storage locations. Specifically, but notexclusively, the present invention relates to a hard disc storage devicecontaining a magnetic storage disc; basically, however, the principlesunderlying the present invention are also applicable to optical storagedevices.

As is commonly known, a storage disc comprises a plurality of tracks,either in the form of a continuous spiral or in the form of multipleconcentric circles, of storage space where information may be stored inthe form of a data pattern. For writing information in the storage spaceof the storage disc, or for reading information from the disc, a discdrive comprises, on the one hand, rotating means for rotating the disc,and on the other hand pickup means for scanning the storage tracks.Since the technology of storage discs in general, the way in whichinformation can be stored in an optical or magnetic disc, and the way inwhich optical or magnetic data can be read from an optical or magneticdisc, is commonly known, it is not necessary here to describe thistechnology in more detail.

In the case of a magnetic disc, the pickup means typically comprise amagnetic head mounted on an actuator arm which is movable in a planeparallel to the disc surface. Usually, the actuator arm is pivotablewith respect to an axis parallel to the disc rotation axis. The magnetichead is capable of converting an electrical signal to a magnetic fieldfor magnetizing an area of the disc in order to write a data pattern(write operation), and is capable of converting magnetic fieldfluctuations to an electrical signal when reading back a data pattern(read operation).

During a write or read operation, audible noise is generated. Noisecontributions may originate from several sources. The magnetic pickupinteracts with the rotating disc, causing vibrations of the disc. Atrack following servo system, continuously adjusting the position of theactuator arm to keep the pickup on track, causes vibrations of theactuator arm, which are transferred mechanically to a carrying frame anda housing. Quick jumps from one track to another, indicated as “seek”action, cause a rattling noise of the actuator arm, which is likewisetransferred mechanically to the carrying frame and the housing. Thesenoises, depending on context, may be annoying to a user.

Therefore, a main objective of the present invention is to limit suchnoises.

The problem mentioned above is already described in, for instance, U.S.Pat. No. 6,396,653, which publication also describes quite elaboratelythe general constructional design of a hard disc drive. In order toreduce said problem, said document discloses a method for optimizing avelocity profile for use in seek actions, especially during idleoperations, the method being performed by a controller within the harddisc device itself.

The phrase “optimizing” in the above means: optimizing with a view tominimum noise production. It may be that an amended velocity profilewill result in reduced noise, but such method involves reducedaccelerations and hence increased seek times, which is certainly notalways acceptable.

The present invention proposes a different approach, which may be takenin stead of or in addition to the above prior art approach.

The present invention is particularly concerned with a consumerapparatus in which a hard disc drive unit (HDDU) is incorporated. By wayof non-limiting example, a television apparatus is mentioned,incorporating a HDDU for storing sound and image (Audio/Video) oftelevision programs. In such application, speed of data transfer is ofgreat importance.

The HDDU can act as an AV recorder for recording TV programs, either forlong-term storage (keeping a recording in archive), mid-term storage(keeping a recording for playback within a few days), or for short-termstorage (playback while recording is still going on). It is noted thatalso in the case of long-term or mid-term storage, a new program may berecorded while an old program is played, in which case playback alsooccurs while recording is going on. The phrase short-term storage isused for a case when a user is watching a program but wishes to take abreak while the program continues: the program is recorded, and when theuser returns he wishes to continue watching where he has left. Then, arecording is played back a short delay time after having been recorded,the delay time corresponding to the duration of the user's break;consequently, also the jump distance for the pickup corresponds to theduration of the user's break. This type of combined write/read operationis also indicated as “time shift”.

In a straight-forward recording or playback operation, the number ofseek actions can be relatively low, as writing or reading, respectively,can in principle be done in a “straight” line, i.e. always following onetrack. However, in the case of concurrent playback and recording, thenumber of seek actions will be relatively large, since the pickupcontinuously needs to jump back and forth from a write location to aread location.

In such consumer apparatus, any high level of “mechanical” noise isunacceptable. Therefore, there is a need to provide a consumer apparatuswith built-in HDDU with reduced noise.

A storage location on disc can be characterized in terms of track numberand sector number. A track number corresponds to a certain radial tracklocation. It has been found that the level of noise generated depends,inter alia, on the radial location where the pickup is operating orjumping. Each HDDU has its own sound profile, representing the amount ofnoise as a function of place. However, in the case of several HDDUs ofthe same type, in practice the several sound profiles are very similaror even identical. Further, even when comparing different types of HDDUswith each other, the sound profiles are generally similar in that thenoise level associated with mid-disc operation is substantially lowerthan the noise level associated with inner-disc or outer-disc operation.In this respect, the phrase “inner disc” relates to a disc area adjacentthe innermost track, the phrase “outer disc” relates to a disc areaadjacent the outermost track, and the phrase “mid-disc” relates to acentral disc area around a central track.

In a consumer apparatus, a HDDU is a separate module, usuallymanufactured by a specialized HDD manufacturer, and usuallyinterchangeable with other HDDUs. Data communication to and from theHDDU is performed by a scheduler of the consumer apparatus. When data isto be stored, the scheduler sends the data to the HDDU, and also sends acommand regarding the desired storage location. The HDDU is expected tobehave as an obedient slave to the scheduler, in that the data receivedis written at the location specified by the scheduler. Only if thetarget location specified by the scheduler appears to be defective, theHDDU is allowed to choose a reallocation location. The scheduler alsonotes where the data was stored. When this data is to be retrieved, thescheduler sends a read command to the HDDU, including informationregarding the locations to read.

The present invention proposes to modify the scheduler such as to takeinto account the sound profile of the HDDU in cases where low noiseproduction is important. Also, the scheduler may take into accountcircumstances like type of action to be performed, time of day, etc. Forinstance, in the case of a time-shift write/read operation, thescheduler may be designed to select the mid-disc area for recording.

These and other aspects, features and advantages of the presentinvention will be further explained by the following description of thepresent invention with reference to the drawings, in which samereference numerals indicate same or similar parts, and in which:

FIG. 1 schematically illustrates a consumer apparatus,

FIG. 2A schematically illustrates a part of a storage disc,

FIG. 2B schematically illustrates the storage space of the storage disc,

FIG. 3A schematically illustrates the storage space of the storage disc,

FIG. 3B schematically illustrates a recording operation,

FIG. 4A schematically illustrates the storage space of the storage disc,

FIG. 4B schematically illustrates a recording operation,

FIGS. 5A-D schematically illustrate the storage space of the storagedisc,

FIG. 6A schematically illustrates a recording operation in case of adefect according to prior art, and

FIG. 6B schematically illustrates a recording operation in case of adefect in accordance with the present invention.

FIG. 1 schematically illustrates a consumer apparatus 1, which for thesake of exemplary discussion may be considered to be a televisionapparatus, comprising a storage facility provided by a built-in HDDU 20.For controlling the data traffic to and from the HDDU 20, the apparatus1 comprises a scheduler 10, which communicates with the HDDU 20 over acommunication link 30. The communication from scheduler 10 to HDDU 20comprises data for storage, storage commands, playback commands; thecommunication from HDDU 20 to scheduler 10 comprises playback data anderror messages.

As will be clear to a person skilled in the art, data signals andcommand signals are actually mixed according to a predefined format indigital communication. However, for sake of clarity, the transfer ofdata and commands will be considered as different communicationchannels, with corresponding inputs and outputs of the scheduler 10 andthe HDDU 20. Thus, it will be considered that the scheduler 10 has adata output 11 for data to be written, a write command output 12 forissuing write commands, a read command output 13 for issuing readcommands, a data input 14 for receiving playback data, and a statusinput 15 for receiving status information, error messages, and the like.Further, it will be considered that the HDDU 20 has a data input 21 forreceiving data to be written, a write command input 22 for receivingwrite commands, a read command input 23 for receiving read commands, adata output 24 for outputting playback data, and a status output 25 foroutputting status information, error messages, and the like. A writedata link 31 connects the scheduler's data output 11 to the HDDU's datainput 21; a write command data link 32 connects the scheduler's writecommand output 12 to the HDDU's write command input 22; a read commanddata link 33 connects the scheduler's read command output 13 to theHDDU's read command input 23; a read data link 34 connects the HDDU'sdata output 24 to the scheduler's data input 14; a status link 35connects the HDDU's status output 25 to the scheduler's status input 15.

The apparatus 1 further comprises user input means 2, which suitably maycomprise command buttons, switches, a key board, etc, allowing the useto express his wishes. The various buttons etc are not shownindividually for sake of simplicity.

The apparatus 1 further comprises a program input 3, for receiving anAudio/Video program, for instance from an antenna, a cable distributionnetwork, etc. Through a data processing circuitry 4, a received programstream is forwarded to the scheduler 10.

The apparatus 1 further comprises a program output 6, for providing aprogram output signal to a rendering device such as a display screen, aloudspeaker, etc. Through a data processing circuitry 5, the scheduler10 forwards data to the output 6.

FIG. 2A schematically shows a plan view of a part of a disc 40 of theHDDU 20. It is noted that the HDDU may contain one or more of suchdiscs. The disc 40 contains, as is generally known, a plurality oftracks, which are not shown individually for sake of simplicity. Anoutermost track 41 defines an outer radius of a recordable disc area 46,while an innermost track 45 defines an inner radius of this recordabledisc area 46. The recordable disc area 46 comprises an outer areaadjacent the outermost track 41, indicated as outer disc area OD 42; aninner area adjacent the innermost track 45, indicated as inner disc areaID 44; and a central area between OD 42 and ID 44, indicated as mid-discarea MD 43. By way of example, it may be assumed that the OD 42, MD 43and ID 44 have mutually the same radial size.

In FIG. 2B, the recordable disc area 46 is schematically illustrated asa straight ribbon.

FIG. 3A is a representation similar to FIG. 2B, illustrating operationof a prior art scheduler. Suppose that the disc 40 is still blank, andthat the scheduler receives a command to record a first program 51. Suchprior art scheduler may start writing from the first available addressin the recordable disc area 46, for instance starting from the innertrack 45 outward, i.e. in the inner disc area ID 44.

FIG. 3B shows the recording 51 on a larger scale. A, C, E, B, D arepoints on the ID 44. The vertical axis represents time. The movements ofa pickup are shown as a path in the Figure.

Suppose that, initially, the user only wishes the apparatus 1 to recordthe program 51; writing then continues gradually from a startpoint Aonwards, illustrated as a sloping line from A to B.

Suppose that, when recording has progressed to point B, the user wishesto start viewing the program 51. The scheduler then orders a playbackfrom starting location A to a location C to fill a playback buffer (notshown) while the input program is stored in a write buffer. The pickupjumps to location A, illustrated as a horizontal line from B to A, andmoves gradually from point A to point C during playback, illustrated asa sloping line from A to C.

The scheduler then continues writing from location B to a location D,reading the data to be stored from the write buffer, while display ofthe program continues from the playback buffer. The pickup jumps tolocation B, illustrated as a horizontal line from C to B, and movesgradually from point C to point D during writing, illustrated as asloping line from B to D.

This procedure is continued as long as simultaneous writing and readingcontinues. It involves repeated seek operations, i.e. jumps from B to A,from C to B, from D to C, etc. These jumps generate noise.

FIGS. 4A and 4B are representations similar to FIGS. 3A and 3B,respectively, illustrating operation of a scheduler 10 in accordancewith the present invention, being set for the same task. Instead ofstarting at the first available address in the recordable disc area 46,the scheduler 10 of the present invention is designed to select theaddress of startpoint A on the basis of minimum noise considerations. Ina simple embodiment, the scheduler 10 may select startpoint A in thecenter of MD 43. In a more elaborate embodiment, the scheduler 10 mayhave an associated memory 7 comprising noise profile data of the disc40, in which case the scheduler 10 may select startpoint A to coincidewith a lowest-noise track, i.e. a track associated with the lowestamount of noise generation.

Again, in a time-shifted playback mode, jumps from B to A, from C to B,from D to C, etc are made, these jumps creating noise. However, thenoise level is reduced as compared with prior art, because the recordingis made in a low-noise area, i.e. MD 43.

It may be that the user wishes to keep the first program 51 for a longertime, even after playback. Suppose that, some time later, the userwishes to record a second program. In the prior art, such second program52 would be stored starting from a location where the previous program51 ended (FIG. 3A). According to the present invention, such secondprogram is also written in a low-noise area, with the lowest amount ofexpected noise. However, it is inevitable that the preferred mid-discarea 43 gets full when it is being filled by writing. This would meanthat later programs can not be stored at the preferred location anymore.

According to a preferred aspect of the present invention, the scheduler10 is designed to copy the recording of first program 51 to anotherlocation outside the preferred low-noise area 43, for example to alocation 51′ adjacent the outer track 41 (see FIG. 5A). Then, thepreferred low-noise area MD 43 is free for the scheduler 10 to write thesecond program 52 (see FIG. 5B).

In the following, the low-noise area MD 43 will also be indicated withthe phrase “quiet area”, while all parts of the recordable disc area 46outside said low-noise area MD 43 will in general be indicated as noisyarea 47.

It is noted that, in the Figures, the size of the programs is shownexaggeratedly large in comparison to the size of the storage areas. Inreality, a quiet storage area 43 is capable of containing many recordedprograms. Nevertheless, the storage capacity in quiet storage area 43 isnot indefinite, and it may be desirable to relocate one or more programsfrom quiet area MD 43 to noisy area 47. This applies especially toprograms which are intended for long-term storage. Therefore, in aspecial embodiment of the present invention, the scheduler 10 is capableof receiving from user input 2 a signal indicating a user-intentionregarding term of storage (i.e. whether a recording is intended forlong-term storage, for instance), and to selectively relocate programsprimarily only if indicated for long-term storage. If more storagecapacity of the quiet area 43 needs to be made available for recording,the scheduler 10 may relocate programs which are indicated for mid-termstorage.

Relocating a recording from quiet area 43 to elsewhere (51 to 51′) isdone by the scheduler 10 at a moment when the user is not using theapparatus 1, and user commands are not expected, for instance when theuser has put the apparatus in a sleep mode or idle mode. In order toassure that possible noise generated by the relocation process is aslittle disturbing as possible, the scheduler 10 may be provided with atime-of-day clock 8, and may be designed to restrict any relocationprocess to a predetermined period. This period may for instance be adaytime period, for instance between 09:00 and 16:00; this is a suitablechoice for cases where the user appliance is located in the user'sbedroom. Alternatively, said period may be selected to be a nightperiod, for instance between 01:00 and 06:00; this is a suitable choicefor cases where the user appliance is located in the user's living room,based on the assumption that the user is not present in that room duringthe night.

It may even be that the hours of said period are user-selectable.

Even in a straight-forward recording or reading mode, i.e. withouttime-shift write/read, reading or writing a disc causes noise (spinningnoise), which noise is less in a quiet area 43 as compared to the noisyarea 47. Therefore, always writing in the quiet area 43 may be adesirable strategy. However, depending on circumstances, it may be thatnoise considerations do not play an important role, and in such casesthe scheduler may be designed to opt for another strategy. For instance,in the case of a program being recorded during a time of day when a useris away, any noise generated will not annoy the user. In such case, itmay be desirable to write the program in noisy area 47, so that quietarea 43 is not used in this case, and the possible need for relocationis avoided.

In this respect, the scheduler 8 may be provided with a time-of-dayclock 8, and may be designed to determine whether noise considerationsapply on the basis of the time of day.

Also, when the user inputs a command to the scheduler to record acertain program, the scheduler may be designed to receive user inputindicating whether the program is to be recorded in a silent mode orwhether the user is indifferent about the amount of noise generated.

In the above, it is explained that a scheduler in accordance with thepresent invention is capable of always recording a program 52 in a quietarea MD 43, because earlier recordings (51) may be relocated (51′) to alocation outside such quiet area MD 43 (provided, of course, that thedisc 40 still has storage capacity inside such quiet area MD 43). As aconsequence, many programs will be stored in noisy area 47. As explainedabove, this applies primarily to programs indicated for long-termstorage. When such programs are to be played, annoying noise may beexperienced when the program is played in a time-shift mode as explainedearlier.

Therefore, it is desirable that a program is located in quiet area MD 43when being played. In order to offer this advantage, a scheduler 10according to a further elaboration of the present invention is designedto be capable of receiving from user input 2 a signal indicating auser-intention regarding time of playback (for instance intended date ofplayback), and to record into said quiet area MD 43 a copy of a programindicated for playback. This operation is illustrated in FIGS. 5C-D.FIG. 5C illustrates that the second program 52 has been relocated (52′)to noisy area 47, in this case ID 44, so that quiet area 43 is fullyavailable for recording. FIG. 5D illustrates that a copy 51″ of therelocated first program 51′ has been recorded in quiet area 43.

The time of the copying process may be selected in a manner similar asdescribed above with respect to the relocation process from quiet areato noisy area.

It is noted that the relocation process is, in fact, a copying process.In the case of relocation (51→51′), the original recording (51) is nolonger needed, and the storage space occupied by the original recordingis made available for future recordings. In contrast, in the case ofcopying (51′→51″) a program from noisy area to quiet area beforeplayback, it is very well possible that the user wishes to keep thisprogram longer. Then, the original recording (i.e. the recording 51′ inde noisy area) is to be maintained. The copy recording 51″ (i.e. therecording in de low-noise area) may be discarded directly afterplayback, but it may also be that the user wishes to play this programonce more in the near future, in which case it is more efficient tomaintain this copy recording 51″ also, for a second or further playback.

It is noted that jumps from one location to another, such as explainedwith reference to FIGS. 3B and 4B in the context of time-shiftwrite/read, are not the only source of noise. Even without such jumps,reading or writing a disc causes noise (spinning noise), which noise isless in a quiet area 43 as compared to the noisy area 47. However, jumpsare an important source of noise, and therefore it is desirable toreduce the occurrence of jumps as much as possible.

In the above, recording and playing are depicted (FIG. 3B, FIG. 4B) asinvolving a relatively smooth movement of pickup over the storage area46. However, as will be known to persons skilled in the art, the storagearea is divided into blocks having a certain address, and in practice itmay happen that one or more blocks are defective so that recording isnot possible there. In order to handle such a situation, a disc 40contains one or more areas where blocks are reserved for use asreplacement of a defective block.

FIG. 6A is a graph similar to FIG. 3B but on a larger scale. Thehorizontal axis indicates storage locations, wherein individual blocksare indicated as Bi, i being an integer index distinguishing individualblocks. SA indicates a spare area, containing reserved blocks Ri.

Suppose that block BN is defective. Normal recording takes place forblocks B(N−2), B(N−1), until block BN is reached, indicated by a firstsloping line 61. The data intended for block BN are recorded in areplacement block Rx, indicated by a second sloping line 62, after whichnormal recording continues for blocks B(N+1), B(N+2), etc, indicated bya third sloping line 63. This replacement recording involves a firstjump from block BN to spare area SA, indicated by a first horizontalline 64, and a second jump back from spare area SA to block B(N+1),indicated by a second horizontal line 65. Of course, the defective areamay be larger than just one block.

Reallocation of the data intended for storage in block BN to areplacement block Rx takes place in the HDDU 20. Normally, the scheduler10 does not have any control over such reallocation operation. In fact,it may even be that the HDDU 20 does not communicate to the schedulerthe fact that reallocation has taken place. However, in a preferredarrangement, the HDDU 20 communicates to the scheduler 10 the fact thatreallocation has taken place, and the HDDU 20 may even communicate tothe scheduler 10 the reallocation address Rx for this defective blockBN.

In a preferred embodiment, the scheduler 10 is designed to avoid writingin defective blocks in order to avoid the occurrence of reallocationjumps. In a defective area memory 9 associated with the scheduler 10,the scheduler 10 stores a list of addresses of blocks BN which,according to information received from the HDDU 20 during writing orreading, are defective. During a write operation, the scheduler 10consults this defective area memory 9. When writing has progressed toblock B(N−1), the scheduler 10 will know from the defective area memory9 that the next block BN is defective, and the scheduler 10 will skipthis block (line 66) and continue writing at block B(N+1) (line 67).This operation is illustrated in FIG. 6B.

It should be clear to a person skilled in the art that the presentinvention is not limited to the exemplary embodiments discussed above,but that various variations and modifications are possible within theprotective scope of the invention as defined in the appending claims.

For instance, in the above, the present invention is explained mainly inthe context of noise generated by jumps (seek noise). However, noise mayalso be generated due to the vibrational modes of the spinning disc,which may be excited due to the position of the pickup and itsdisturbing effect on the airflow which causes forces exerted on thedisc.

In the above, the operation of the scheduler in accordance with thepresent invention is explained mainly in the context of seeking aspecific location for writing information. However, the presentinvention is not limited to writing operations. It may be that a certainprogram is stored in more than one location on disc; this is especiallythe case if the scheduler has performed a relocation of a program, asexplained in the above. Then, if the scheduler receives a read command,it has a choice between two or more program locations; in accordancewith the present invention, the scheduler will read the program from theprogram location associated with the least noise.

In the above, the operation of the scheduler in accordance with thepresent invention is explained mainly in the context of seeking aspecific location for writing or reading information. Apart fromselecting a storage location where the seek noise will be minimal, it isalso possible that the seek strategy is adapted to circumstances, with aview to noise generation. For instance, the amount of seek noisegenerated in the more-noise area 42, 44 may be reduced by reducing theseek rate.

In the above, it is explained that a scheduler according to the presentinvention is noise-aware, and is capable of operating in a quiet mode inwhich the scheduler makes choices on the basis of minimizing the amountof noise involved. It is possible that the scheduler is always operatingin such quiet mode. However, there are circumstances where such quietmode is not necessary. For instance, it may be that quiet mode is notnecessary during daytime, when it is expected that noise from thesurroundings will camouflage the seek noise, whereas operation in quietmode is required during night. It is also possible that the scheduler isassociated with a means for ascertaining the presence/absence of peoplein its vicinity, in which case the scheduler may be designed to operatein quiet mode when it determines that at least one person is present orto operate in a non-quiet mode when it determines that no persons arepresent. Thus, a scheduler in accordance with the present invention ispreferably capable of operating in at least two modes, a first mode orquiet mode wherein the scheduler is noise-aware and makes choices with aview to noise-reduction, and a second mode or non-quiet mode wherein thescheduler does not take any considerations of noise-reduction intoaccount when making choices.

It is possible that the decision whether to operate in quiet mode or innon-quiet mode is user-selectable. It is also possible that thescheduler is capable of deciding itself to operate in quiet mode or innon-quiet mode on the basis of one or more predetermined criterions.

In the above, the present invention is explained with reference to noisegeneration as being annoying to humans. However, writing and readingoperations are also associated with mechanical vibrations, which maydisturb or interfere with other devices which are sensitive tovibrations. For such cases, the same considerations apply to vibrationsas mentioned above in the context of noise. Therefore, in this text,especially in the claims, the expression “amount of noise” will alsomean “amount of vibrations”.

Thus, the present invention succeeds in providing a scheduler 10 for auser appliance 1, and a user appliance comprising such scheduler, forco-operation with a disc storage device 20. The scheduler is designed toperform a quiet writing/reading strategy, i.e. to record or read userdata into or from storage space of the rotary disc storage device, atstorage locations where the amount of noise generated is as little aspossible. The scheduler has an associated memory 7 with information onthe noise behavior of the disc storage device 20 as a function of thestorage location. When selecting a storage location for writing orreading, the scheduler is designed to consult the memory 7 and to selecta quiet storage area 43.

1. Scheduler for an apparatus comprising a disc storage device, thescheduler being designed for receiving data and writing the data instorage space of a storage medium of the disc storage device; thescheduler being designed to operate in a first mode wherein thescheduler, when setting at least one operating parameter, sets suchoperating parameter with a view to low noise generation.
 2. Scheduleraccording to claim 1, wherein the scheduler is always operating in saidfirst mode.
 3. Scheduler according to claim 1, the scheduler also beingcapable of operating in at least a second mode in which the scheduler,when setting said operating parameter, sets said operating parameterwithout noise reduction.
 4. Scheduler according to claim 3, wherein thescheduler, when operating in said second mode, sets said operatingparameter to a value or selection different from the one when operatingin said first mode, while the value or selection of said operatingparameter as set in said first mode results in an amount of noisegeneration less than the amount of noise associated with the value orselection of said operating parameter as set in said second mode. 5.Scheduler according to claim 2, wherein the operative mode of thescheduler is user-selectable, and wherein the scheduler is responsive touser input to select its operative mode as either said first mode orsaid second mode.
 6. Scheduler according to claim 2, wherein thescheduler is capable of determining the presence of at least one personin the vicinity of the said apparatus, and wherein the scheduler isdesigned to select its operative mode as said first mode when itdetermines the presence of at least one person, and wherein thescheduler is designed to select its operative mode as said second modewhen it determines the absence of persons.
 7. Scheduler according toclaim 2, provided with a time-of-day clock, the scheduler being designedto select its operative mode depending on the time of day.
 8. Scheduleraccording to claim 1, the scheduler being designed to generate writecommands for the disc storage device, wherein said at least oneoperating parameter is a target address of a storage location in saidstorage space where the data is to be written to.
 9. Scheduler accordingto claim 1, the scheduler being designed to generate read commands forthe disc storage device, wherein said at least one operating parameteris a target address of a storage location in said storage space wherethe data is to be read from.
 10. Scheduler according to claim 8, whereinthe scheduler is associated with a memory containing information on asound characterization of the disc storage device; wherein the scheduleris designed, when operating in said first mode, to consult theinformation in said memory when selecting a target address of a storagelocation in said storage space.
 11. Scheduler according to claim 8,wherein the disc storage space comprises quiet area and noisy area; andwherein the scheduler is designed, when operating in said first mode, ifthere is sufficient storage space available in said quiet area as wellas in said noisy area, to select target addresses within said quiet areaof the storage space.
 12. Scheduler according to claim 11, wherein thescheduler is designed, in said second mode, to select target addressesoutside said quiet area of the storage space.
 13. Scheduler according toclaim 8, wherein the disc storage space comprises mid-disc area, innerdisc area and outer disc area; wherein the scheduler is designed, whenoperating in said first mode, if there is sufficient storage spaceavailable in said mid-disc area as well as in said inner disc area orouter disc area, to select target addresses within said mid-disc area ofthe storage space.
 14. Scheduler according to claim 13, wherein thescheduler is designed, in said second mode, to select target addressesoutside said mid-disc area of the storage space.
 15. Scheduler accordingto claim 11, wherein the scheduler is designed to relocate a recordingfrom a quiet area of the storage space to a noisy area of the storagespace.
 16. Scheduler according to claim 15, wherein the scheduler isdesigned to perform such relocation process in response to receivinguser input indicating that the recording is intended for long-termstorage.
 17. Scheduler according to claim 11, wherein the scheduler isdesigned to copy a recording from a noisy area of the storage space to aquiet area of the storage space.
 18. Scheduler according to claim 17,wherein the scheduler is designed to perform such copying process inresponse to receiving user input indicating that the recording is to beplayed in the near future.
 19. Scheduler according to claim 15, whereinthe scheduler is designed to perform such relocation or copying processduring an idle moment.
 20. Scheduler according to claim 15, providedwith a time-of-day clock, the scheduler being designed to perform suchrelocation process during a predetermined time slot.
 21. Scheduleraccording to claim 20, responsive to user input to set said time slot infuture.
 22. Scheduler according to claim 1, the scheduler beingdesigned, when operating in said first mode, to reduce seek movementswhen writing/reading in/from a noisy area and to increase seek movementswhen writing/reading in/from a quiet area
 23. Apparatus comprising adisc storage medium and a scheduler according to claim
 1. 24. Apparatusaccording to claim 23, wherein the disc storage medium comprises a harddisc drive unit.